Fire Ants Win Out Through Land Changes, Not a Better Build

Walter R. Tschinkel

A nest of fire ants, “disturbance specialists,” in Tallahassee, Fla.

Fire ants love a disturbance. Plow up some ground just about anywhere in the South, and chances are the red imported fire ant, Solenopsis invicta, will take over from native ant species. That’s why S. invicta, a major invasive pest, is found in subdivisions, shopping centers and other areas where the natural environment has been disturbed.

But is it the human-caused disturbance that makes S. invicta have such a negative impact on other ants, or something about the ant itself? One school of thought holds that the reason many invasive species succeed is that they are superior to other species and can outcompete them no matter what the situation.

A large study by Joshua R. King and Walter R. Tschinkel of Florida State shows that for fire ants, at least, human disturbance of the environment is the main force behind their negative impact.

They demonstrated this by introducing fire ants into forest plots that were mowed and plowed. In The Proceedings of the National Academy of Sciences, they report that plowing by itself reduced the number and diversity of native ants greatly. Fire ants by themselves had less of an effect.

The researchers suggest that fire ants may not be so much an invasive species but a “disturbance specialist,” and that other species may fit that description, too.

By HENRY FOUNTAIN

Original here